    function checkLogin(){
        username=document.formLogin.username;
        password=document.formLogin.password;
        if(username.value==""){
            alert("Username mustn't is empty !");
            username.focus();
            return false;
        }
        if(password.value==""){
        	alert("Password mustn't is empty !");
            password.focus();
            return false;
        }
        return true;
    }